Frame looks like this electrified cargo bike from Walmart. Probably some unknown brand out of China. Not a Bakfiets since they have a different frame design.
https://www.walmart.com/ip/Classic-E...ycle/371872054
I think $300 is a great deal. At this price you can always upgrade to better components. As for brakes I would just fiddle with them. Mechanical rim brakes are not difficult to adjust.